Merge pull request #9557 from jhawk28/bug_9547

unset HardwareConfig.Firmware for vsphere-iso

builder/vsphere/iso/builder.go

@@ -60,6 +60,11 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (pack
 		)
 	}
 
+	// default Firmware to "" since it is already configured by the CreateConfig.Firmware
+	if b.config.CreateConfig.Firmware != "" {
+		b.config.HardwareConfig.Firmware = ""
+	}
+
 	steps = append(steps,
 		&StepCreateVM{
 			Config:   &b.config.CreateConfig,